This 5-year K01 Mentored Research Scientist Development Award integrates an extensive Training and Research Plan. The candidate is in need of additional mentored training to become an independent researcher in the area of brain imaging, sleep medicine and drug abuse. Hence, the Training Plan combines comprehensive training in clinical laboratory research, sleep recording techniques, and functional magnetic resonance imaging (fMRI) technology. The Research Plan is designed to help the candidate implement the skills outlined in the training plan and proposes to examine the effects of sleep deprivation on cue-reactivity and subjective drug craving by collecting electroencephalogram measures of event-related potentials and fMRI blood-oxygen-level-dependent brain activation patterns in a population of marihuana-dependent persons. Both the acute and chronic use and abuse of drugs impact sleep, but the literature currently lacks reports of rigorous investigations of the impact of sleep deprivation on indices of drug use, craving, and relapse. The experimental goals would test the hypothesis that sleep deprivation in marihuana-dependent subjects results in enhanced cue-reactivity and/or subjective drug craving and subsequent differences in regional activation patterns in specific brain reward circuitry. This is an important research objective as enhanced drug cue-reactivity and craving following sleep deprivation may perpetuate drug-taking behavior and/or increase the incidence of relapse. The implications of these findings may suggest that more attention may need to be paid to a patient's sleep disorders in developing effective treatments for drug dependence. Drug craving and the physiological response to drug-related cues are contributing factors to drug taking behavior and relapse in drug abstinence. The proposed Research Plan would test whether sleep deprivation in marihuana-dependent individuals increases their response to marihuana-related pictures using electroencephalogram (EEG) measurements of brain electrical activity and functional magnetic resonance brain imaging. The findings would show the strong relationship between sleep loss and drug craving that is of great importance in developing effective drug treatment strategies and may provide insight to those struggling with drug abuse and/or dependence in understanding the contribution of sleep/wake patterns to their drug-taking behavior.